submodules path in gitdir is wrong (was: Submodules not having any objects)

[Cromel]

When you use submodule and get repository it doesnt contain any objects like commits and etc.
It must be becouse they are contained in models directory https://git-scm.com/docs/git-submodule#git-submodule-absorbgitdirs, when in code it is hardcoded "module" in file storage/filesystem/internal/dotgit/dotgit.go
Is it intended in such a way or its a bug?

[smola]

@Cromel Thank you for taking the time for filling this bug report!

Could you post here a small code example showing what you're doing?

[Cromel]

@smola yes, no problem. For example such code doesn't print any commits in repo with submodules:

` path := "some repo with submodules"

r, _ := git.PlainOpen(path)
wt, _ := r.Worktree()
submodules, _ := wt.Submodules()
for _, submodule := range submodules {
	subRep, _ := submodule.Repository()
	commits, _ := subRep.CommitObjects()
	commits.ForEach(func(c *object.Commit) error {
		fmt.Println(c)
		return nil
	})
}`

[smola]

@Cromel Using submodules in a repository requires initializing them (as in git submodule init or git clone --recurse-submodules). Does the repository in path have initialized submodules?

If it does not, you'd have to add the following:

// after getting submodules
err := submodules.Init()
checkErr(err)
err := submodules.Update(&SubmoduleUpdateOptions{})
checkErr(err)

Check SubmoduleUpdateOptions for possible options. Also, if you're cloning with go-git, consider using RecurseSubmodules in CloneOptions.

[Cromel]

@smola repo was cloned using git clone --recurse-submodules , so there are initialized. The problem is with where submodules info is stored. If i change the line in file storage/filesystem/internal/dotgit/dotgit.go
from
modulePath = "module"
to
modulePath = "modules"
its starts working. But i dont know that it is a bug or i do something wrong when i am using submodules.

[smola]

@Cromel Right. It is indeed a bug. It should be modules, so it works if you initialize (with the wrong path) from go-git, but not if it was initialized from git.

Your proposed fix seems correct. Will you create a PR?

[Cromel]

@smola Created PR